The present invention relates to a production control apparatus and method used in factories, etc. for manufacturing products.
In recent years, manufacturing electric appliances, etc. has required a very large number of parts since their sophistication and performance have been increased. In the case of production of a hard disk drive, for example, a considerable number of parts must be prepared to assemble even the head stack assembly alone.
To help manufacture such a product, components lists are used at both the design stage and the manufacturing stage. Examples of such components lists include the e-BOM (engineering Bill of Material), which is used at the design stage, and m-BOM (manufacturing BOM), which is convenient for use in production of a product.
These components lists store, for each type of component in the product, technical information, information on a standard component (or a primary candidate component, i.e., a component to be normally selected), and information on substitute components (or secondary candidate components) for substituting for the standard component, etc.
FIG. 9 shows an exemplary components list. The components list in FIG. 9 includes information on two types of components, A and B. As shown in FIG. 9, a primary candidate a1 and five secondary candidates a2 to a6 are listed for the component A, while a primary candidate b1 and a secondary candidate b2 are listed for the component B.
Further, this list also includes information on which one or ones of the primary and secondary candidate components may be used to satisfy the specifications requested by each customer. For example, in the case of customer X, the component A may be the primary candidate a1 or any one of the five secondary candidates a2 to a6, and the component B may be either the primary candidate b1 or the secondary candidate b2.
In the case of customer Y, on the other hand, the component A may be selected from among only the primary candidate a1 and the secondary candidates a3 and a6, though the component B may also be either the primary candidate b1 or the secondary candidate b2.
Thus, the above components list, which does not discriminate between primary and secondary candidate components, may provide information on candidate components which may be used to satisfy the specifications requested by each customer, and may assign a common component item code to the candidates for the same component. This allows easy handling of a components list at the design stage.
Such an arrangement, however, causes a problem at the manufacturing stage, since, for example, the components list assigns a common component item code to all of the primary candidate a1 and the secondary candidates a2 to a6 for the component A, even though they are different components. Therefore, the components list cannot provide information on how many primary candidate components a1 and secondary candidate components a2, etc. are to be ordered for the production. Thus, this list is not suitable for drafting a production plan, which must specify the number of components of each type to be used or ordered.
To overcome the above problem, a different component item code may be assigned to each (candidate) component. In such a components list, for example, 6 different component item codes are assigned to the primary candidate a1 and the secondary candidates a2 to a6, respectively, though these candidate components are used as the same component A. This allows drafting of a plan which specifies the number of components of each type to be used or ordered. However, changing this type of components list requires a large amount of management work. Furthermore, to accommodate the specifications requested by each customer, the list must store information on which candidate components are to be used for each product (for each customer).